Gupta K C, Jeanne D'Arc M
Polymer Research Laboratory, Department of Chemistry, University of Roorkee, Roorkee 247667, Uttar Pradesh, India.
Talanta. 2000 Sep 5;52(6):1087-103. doi: 10.1016/s0039-9140(00)00479-3.
Potential response of cadmium(II) ion selective electrode based on cyanocopolymer matrices and 8-hydroxyquinoline as ionophore has been evaluated by varying the amount of ionophore, plasticizer and the molecular weight of the cyanocopolymer. The sensitivity, working range, response time, and metal ions interference have shown a significant dependence on the concentration of ionophore, plasticizer and molecular weight of cyanocopolymers. The electrodes prepared with 2.38x10(-2) mol kg(-1) of ionophore, 1.23x10(-2) mol dm(-3) of plasticizer and 2.0 g of cyanocopolymer (molecular wt., 59 365) have shown a Nernstian slope of 29.00+/-0.001 mV per decade activities of Cd(2+) ions with a response time of 12+/-0.007 s. Electrodes have shown an appreciable selectivity for Cd(2+) ions in the presence of alkali and alkaline earth metal ions and could be used in a pH range of 2.5-6.5. The cyano groups of the copolymers contributed significantly to enhance the selectivity of the electrode. The electrode has shown an appreciable average life of 6 months without any significant drift in the electrode potential and found to be free from leaching of membrane ingredients. Electrode response is explained considering phase boundary model based on thermodynamic considerations.
基于氰基共聚物基质和8 - 羟基喹啉作为离子载体的镉（II）离子选择性电极的潜在响应，已通过改变离子载体、增塑剂的用量以及氰基共聚物的分子量进行了评估。灵敏度、工作范围、响应时间和金属离子干扰已显示出对离子载体浓度、增塑剂以及氰基共聚物分子量有显著依赖性。用2.38×10⁻² mol kg⁻¹的离子载体、1.23×10⁻² mol dm⁻³的增塑剂和2.0 g氰基共聚物（分子量为59365）制备的电极，对于Cd²⁺离子每十倍活度显示出29.00±0.001 mV的能斯特斜率，响应时间为12±0.007 s。在碱金属和碱土金属离子存在的情况下，电极对Cd²⁺离子表现出明显的选择性，并且可在2.5 - 6.5的pH范围内使用。共聚物的氰基对提高电极的选择性有显著贡献。该电极显示出约6个月的可观平均寿命，电极电位没有任何明显漂移，并且发现没有膜成分的浸出。基于热力学考虑，根据相界模型对电极响应进行了解释。
